The invention generally relates to devices used for carrying paper goods and the like. More particularly, the present invention relates to a loose-leaf binder which retains perforated loose-leaves and notebook paper.
Loose-leaf binders are generally known in the art for use in receiving and retaining a sheaf of papers in an organized, orderly fashion. As one common example, conventional ring binders include a plurality of metal or plastic rings for reception through preformed perforations along one side edge of a sheaf of papers. Such ring binders are used extensively in applications wherein frequent insertion and/or removal of paper sheets from the binder is necessary or desirable. However, such binders exhibit a fixed width or thickness at the binder spine, in accordance with the size of the binder rings, in combination with a variable width or thickness at the open side of the binder in accordance with the number of contained pages. As a result, traditional ring binders do not have a uniform rectangular book-like configuration, and thus are not conducive to stacking or shelving in an orderly manner. Moreover, individual sheets contained within the binder are subject to relatively easy inadvertent tearing from the binder rings.
Alternative binder constructions have been proposed for receiving a variable thickness stack of papers with one side edge clamped securely within the spine of an adjustable binder cover. While these binder constructions beneficially accommodate compilation and binding of papers into a more rectangular book-like configuration, with reduced risk of inadvertent tearing of individual sheets form the binder, these binder constructions require multiple cover components and/or multiple paper retainer pins and related clamp or lock devices which result in a relatively complex and costly binder product.
U.S. Pat. No. 5,333,125 to Forsse et al. discloses a modular book binder which accommodates variable thickness of the bound paper so as to be generally rectangular and conducive to stacking or shelving in an orderly manner. However, such modular binder must have various components of a spine thereof disassembled in order to remove or add paper, after which the spine assembly must be reassembled.
Curled finger binders are old and well-known. Such binders include a spine and overlapping extensions in the shape of curled fingers which are inserted in corresponding rectangular perforations in the paper leaves to be bound and which overlap with one another. Conventionally, a separate uncurling tool is needed to separate the normally overlapping curled fingers, to thereby allow the paper leaves to be inserted therebetween. Once the sheets are inserted between the separated curled fingers, the uncurling tool is removed, allowing the fingers to insert into their corresponding rectangular perforations in the sheets, to encircle them and to once again overlap. This effectively binds the sheets of paper or loose leafs together, and provides them with a spine. The requirement of a separate tool to separate the curled fingers increases the complexity and cost of the binders. Moreover, the owner of the binder is not able to freely add or remove paper from the bound booklet.
U.S. Pat. No. 6,126,353 to Mullin et al., discloses a curled finger hinge binder which does not require the use of a tool. However, the fingers of the Mullin hinge binder must have a very thin cross-section to allow for the overlapping thereof so that the pages do not become bent, distorted or torn. Such overlapping fingers, which arrangement is also used in conventional loose-leaf binders, cause the pages to be hung up in the overlapped fingers as they are turned. Moreover, there appears to be no easy way to open the Mullin hinge binder once it is snapped onto the pages without the risk of breaking the binder.
Accordingly, there is a continuing need for a binder that is simple, easy to use and inexpensive. Such a binder should not require finger opening tools, and should be capable of being opened and closed easily so as to facilitate the addition and removal of pages thereto. The present invention fulfills these needs and provides other related advantages.